PROJECT SUMMARY/ABSTRACT While it is generally recognized that interventions that slow the progression of Alzheimer?s disease (AD) could substantially reduce associated care needs and costs, there has been little progress to date in developing such interventions. Moreover, the notion that Alzheimer?s disease progresses at a similar pace among individuals within any cohort of AD patients is wholly inadequate for characterizing the temporal progression of a broad array of disease symptoms. Accurate characterization of the progression of Alzheimer?s disease must contend with two types of heterogeneity in AD patients?the first reflecting differences in manifest symptoms occurring at the time of diagnosis, and the second reflecting differential rates of progression following diagnosis. The proposed Administrative Supplement to P30AG034424 will focus on five large cohorts of patients with suspected Alzheimer?s disease using data from the 1984, 1989, 1994, 1999, and 2004 National Long Term Care Survey (NLTCS) to identify incident cases using our published AD case selection algorithm for the NLTCS; these analyses will be replicated using comparable data from the 1998?2014 Health and Retirement Study (HRS). Analysis of the NLTCS and HRS falls within the scope of the P30 parent grant; the opportunity to further develop and validate the results from our prior published analyses will meet the urgent public health need for accurate predictions of length of time until AD patients need full-time care and the durations/costs of such care as the severity of the disease increases. This Administrative Supplement has four specific aims: 1. To further develop and validate our published Sullivan life table (SLT) extension of the longitudinal Grade of Membership (L-GoM) model of the progression of Alzheimer?s disease among five cohorts of Medicare enrollees in the NLTCS with incidence of AD at or near the times of field operations of the five waves of the NLTCS?1984, 1989, 1994, 1999, and 2004 with Medicare follow-up to 2009 and mortality follow-up to 2010?using the 80?95 covariates identified in our prior published analyses. 2. To use the SLT/L-GoM model to establish the dimensionality of the AD process among nursing home residents identified in the nursing home Minimum Data Set (NH-MDS) and to test whether the additional data are consistent with the three-dimensional process previously estimated in Aim 1 or if a third type of heterogeneity exists at or near the endpoint of our prior published models. 3. To use the model(s) developed in Aims 1 and 2 to analyze the care needs and costs for AD patients using NLTCS-linked CMS data covering Medicare Parts A and B services and nursing home services identified in the NH-MDS using our published methods for computing inflation- adjusted (i.e., constant dollar) discounted lifetime costs of care at the time of AD onset within the L-GoM framework. 4. To replicate the analyses in Aims 1?3 using comparable data from the 1998?2014 HRS with Medicare and mortality follow-up to 2015.